Six of six sewage samples came back positive. On July 16, 2024, the World Health Organization’s Global Polio Laboratory Network reported traces of circulating vaccine-derived poliovirus type 2 in every sample taken from sites in Khan Yunis and Deir al-Balah, in the Gaza Strip.
Genomic sequencing by the U.S. Centers for Disease Control and Prevention found the samples closely linked to one another. They were also closely related to cVDPV2 that circulated in Egypt through the second half of 2023 and was last detected there in December 2023. Genetic changes in the samples suggested the virus could have reached Gaza as early as September 2023.
Declaration and first case
On July 29 the Gaza Health Ministry declared a polio epidemic. It said the poliovirus in large deposits of wastewater threatened Gaza and neighboring countries, and called the outbreak “a setback to the global polio eradication program”. The ministry blamed Israel’s destruction of hospitals and medical infrastructure. The next day the WHO said it was “very likely” that polio had infected people in Gaza and was spreading, though finding cases would be hard because the virus is asymptomatic in most people and, as the WHO put it, Israeli medical blockades were preventing confirmation.
The WHO reported that immunization coverage in Gaza was 99% in 2022 and fell to 89% in 2023. It listed a lack of security, obstructed access, constant displacement, medical shortages, poor water quality and weakened sanitation.
Late in July, three cases of acute flaccid paralysis were diagnosed in the strip, and samples went to Jordan for analysis. On August 16, tests in Jordan confirmed the first polio infection, in Deir al-Balah in central Gaza. The patient was a 10-month-old baby, described as having “stopped crawling, stopped moving, stopped standing up, and stopped sitting.” The United Nations confirmed one case of paralysis.
Calls for a pause
After the case, the WHO and UNICEF said a pause of at least seven days was needed for mass vaccination, Press TV reported. Hamas said it would support a seven-day truce. The campaign aimed to immunize 640,000 children under 10 over two rounds, starting at the end of August.
On August 29, Israel made a “preliminary commitment” to comply with pauses in fighting to allow the campaign. The WHO reported on September 12 that it had reached its vaccination target for children in the strip.
The Israeli military began a voluntary vaccination program for its soldiers and said it was working with aid agencies on deliveries into Gaza, with about 300,000 vaccines delivered since October 2023. Dr. Lior Nesher of Soroka Medical Center in Beersheba warned that stopping the virus’s “ecological movement” would be “almost impossible” and that it “does not respect borders”. He noted that Israeli measles vaccination rates were below the 92 to 93% herd immunity level.
What came after
A second round began on October 14, 2024, delayed by heavy bombardment in northern Gaza, where it aimed to reach more than 100,000 children. In early November, the WHO said it would resume vaccinations in Gaza City, and an Israeli drone reportedly struck the Sheikh Radwan Clinic a day later. The WHO later said six people, four of them children, were hurt.
By March 2025 no further child cases had been confirmed, but monitoring of wastewater showed the virus was still circulating. A third round, held from February 22 to 26, 2025, reached 602,795 children under ten.
Sources
- Aid groups call for immediate pause in Gaza war for polio vaccination to avert outbreak
- 2024 Gaza Strip polio outbreak – Wikipedia
